The traditional way of building a deck involves screwing through the decking boards to wooden joists beneath. It’s simple and secure but leaves rows of screw heads visible, which some feel spoils the finished appearance.
Hidden fasteners solve the problem. There are several different approaches to hiding fasteners on a deck, and none is particularly complicated. While it’s something that’s best decided during the planning stage, the choice isn’t always straightforward, especially for those who have never seen this type of fastener.
The following article offers comprehensive answers by exploring the qualities of some of the best hidden fasteners for a decking project. Whether you’re using solid wood, composite, or PVC decking, one of the top products listed below may be a fitting choice.
- BEST OVERALL: National Nail Camo 1750-Pro Pack 2 3/8 inch
- RUNNER UP: Starborn Industries Pro Plug System Wood Deck Kit
- BEST FOR COMPOSITES: TREX Hideaway Plastic Fasteners with Screws
- ALSO CONSIDER: TimberTech CONCEALoc Fastener
While all of the hidden fasteners in this guide are relatively easy to install, a variety of different approaches are used. Understanding their strengths and suitability for particular kinds of boards is vital in choosing the best hidden fasteners for a deck. The following section presents the technical and practical aspects of these devices.
Type of Fastener and Application
There are two basic approaches to fixing decking boards with hidden fasteners. The first method is to screw directly through the board into the joist below. The second is to use a clip to hold the board, with that clip screwed to the joist. However, there are variations on each, covered below in more detail.
- Screw and plug systems are usually the cheapest. A special two-stage drill bit counterbores a hole, allowing the screw head to be driven below the surface. A wooden plug is then glued in place, hiding the screw head. If the deck is being finished with a stain, the plugs become difficult to notice. The main drawbacks are that the process is slow, and it cannot be used on composites or PVC.
- A faster approach to fixing through boards and into the joists is to use a guide that allows screws to be driven at an angle through the side of the board so no plug is needed. A guide provides the perfect angle for the screw and also automatically spaces the boards. Most do require the use of a proprietary driver and special screws but can be used in real wood, composite, or PVC boards.
- Clips come in various designs. Most have “wings” that fit in a precut groove in the board. They have a central hole that is used to screw them to the joists. The shape usually incorporates automatic spacing. Usually these clips are used for composite or PVC boards, though a version does exist specifically for softwood.
Board Size and Shape
The size and shape of the decking boards can have a major impact on which hidden deck fastener system is best. With screw and plug systems, the width of the board doesn’t matter at all, but most guides used for drilling through the sides of boards have a limit to the board size they will fit. Standard lumber is called 6-inch-wide, but the actual dimension is 5½ inches wide. It’s important to know what width the guide can accept, especially if using nonstandard-size boards or reclaimed materials.
Shape (or profile) also is important. Clips designed to fit the popular Trex or Azek decking boards may not be suitable for competitor products. Conversely, although money can sometimes be saved by buying hidden fasteners off-brand, fit needs to be checked carefully.
Where slots are not present, a cutter can be used to create them. These tools are readily available, often from the same brand that makes the clip. However, a router will be required, and this adds to the overall job time.
Real wood decks expand and contract as the seasons change. There are a couple of considerations if screws are used directly through the boards. The first concerns softwoods, which are much more prone to movement than hardwoods. As a result, they can become loose over time, so a clip might be a better option. The second concerns oak, which contains tannin that is highly corrosive to ordinary steel screws, so nickel-plated or stainless steel screws should be used.
If clips are being used, the material they are made from has a bearing. Plastic clips are often low cost and generally used with composite or PVC boards. These aren’t subject to the same movement as real wood. Nevertheless, consistent activity on the deck risks eventual fracture, so they may not be the best choice for high-traffic decks. Reinforced nylon or metal alternatives are widely available.
Our Top Picks
Now that you know more about the technical and practical aspects of choosing the best hidden fastener, it’s time to look at real-world examples. Each of the following is a tried-and-tested system that offers a solution for a particular type of decking installation. One of these may be the best choice for your planned deck.
National Nail offers several types of clips for grooved decking. However, this combination of a fastening tool, drivers, and screws provides arguably the fastest and most versatile hidden fastener system currently available.
The handheld screw guide clamps easily onto boards from 5 1/4 to 5 3/4 inches wide and automatically creates a 3/16-inch gap between boards. It can be used with composites, PVC, pressure-treated lumber, or hardwoods.
Patented edge deck screws cut efficiently to virtually eliminate splitting or cracking. The thread is designed for maximum grip in the joists, providing excellent durability regardless of the actual deck material. Two drivers are included in the kit. DIY users benefit from its ease of use; professionals benefit from the system’s speed. The tub contains sufficient screws for around 450 square feet of deck, depending on joist spacing.
Screws have been the preferred fastener for deck boards because they don’t pull out like nails. It’s actually a fairly fast and efficient method, but even well-aligned screw heads spoil the appearance of the finished deck in many people’s view.
The Starborn Industries system takes this effective idea but uses a special counterbore tool that allows the screw head to be sunk below the surface. A tough hardwood plug is then glued on top. The counterbore consistently cuts holes of the correct depth, so no sanding should be needed. Boards will need to be gapped using separate devices.
A variety of plug colors are available to suit different decking timber. Some people choose a contrasting color as a feature. Alternatively, if a stain is applied to the finished deck, the plugs become almost unnoticeable. This starter pack covers around 30 square feet. Larger tubs cover around 100 square feet.
These easy-to-use clips are primarily designed to work with the high-quality, recycled composite boards made by TREX. However, they can work with any board of the same profile (check carefully before purchase). A precision cutter also is available that will allow the correct groove to be cut into solid composite or real wood boards, further extending versatility.
The clips provide a spacing of ¼ inch. They are made of glass-filled nylon, which combines high strength with flexibility so they are far less likely to crack than inexpensive plastic models. A stainless steel screw attaches them to the decking joists.
This pack is sufficient for 50 square feet of deck. A bucket with enough clips for 500 square feet is available for larger installations, and a star driver is included.
TimberTech’s capped composite decking with its tough polymer shell is widely regarded as the product that most closely resembles real wood. Azek’s PVC boards are generally accepted as the most durable. These specially designed fasteners are equally effective at providing hidden fixing for either of these popular boards.
CONCEALoc fasteners are made from heavy-duty stainless steel. They are very strong and highly resistant to corrosion, thus ensuring outstanding durability. While designed for pre-grooved boards, a cutter can be used to make grooves in TimberTech’s plain composite boards if preferred. Gapping ranges from 1/8 to 3/16 inch wide.
The pack contains sufficient clips for approximately 100 square feet of decking. Screws are not provided but are readily available.
In the sections above, many of the important physical factors involved in choosing the best hidden fasteners for decking are described and some practical examples are included. While this will have provided a great deal of useful information, there may still be a few questions. The following are answers to some of those questions that are frequently asked.
Q. How many hidden deck fasteners do I need?
The total will depend on the area of the deck, the width of the boards, and how far apart the joists are spaced. In effect, one fastener is needed for each edge of the board, fixed into each joist. So multiply the number of joists by the number of boards times two.
Q. How do I attach deck boards without any screws showing?
There are three approaches:
- You can counterbore the boards so the screw heads go below the surface, then hide them with a wooden plug that is glued in.
- You can drill and screw at an angle through the edges of the boards and into the joists, so each new board hides the screws of the previous board.
- You can use hidden clips that fit into grooved boards.
Examples of each of these can be found in the top picks section above.
Q. Can I use hidden fasteners on composite decking?
Absolutely. As mentioned above, you can screw through the edges using a precision guide or use hidden fasteners designed specifically for composite decking.
Q. How do I replace deck boards with hidden fasteners?
It depends on the system used. Some can be unscrewed, the old board removed, and a new one installed. In other cases, it may be necessary to cut through the board to be removed and sacrifice existing fasteners before replacement. The flip side of some hidden fasteners is that it can be awkward to remove them. Nevertheless, each manufacturer usually provides relevant information for removal.